Remote sensing and communication system

ABSTRACT

A remote sensing system and method for instrumenting the entries to manhole enclosures, in order to provide a platform and means for sensing environmental parameters within and around the enclosures and wirelessly transmitting those parameters to a distant site. The system comprises a housing with sensor for monitoring environmental parameter in the vicinity of the manhole. A microcontroller in the housing sends the parameters to a radio module, which transmits the parameters to a communication device for alerting a user that a manhole has been tampered with.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of U.S. patent application Ser. No.11/134,691, filed May 20, 2005, the contents of which are herebyincorporated by reference in their entirety.

FIELD OF THE INVENTION

This invention relates generally to a system and method forinstrumenting the entries to enclosures, in order to provide a platformand means for sensing environmental or process parameters within andaround the enclosures and wirelessly transmitting those parameters to adistant site.

BACKGROUND OF THE INVENTION

Sanitation and waste water systems are becoming increasingly expensiveto operate and face daunting environmental, community and regulatorypressures. Agencies and organizations that manage sanitation systemsface complex and costly problems. Three of the main problems facingsanitation system operators are sewage spills, treatment failure, andillegal dumping. The first two of these problems often result inuncontrolled spills of septic materials into the environment, causingenvironmental damage, health risks, and high cleanup and mitigationcosts, while the third problem respectively generates a potential dangerto treatment systems, the environment and uncontrolled liability for thesanitation operators.

Sewage spills are becoming more common and more costly for agencies andorganizations that are responsible for handling waste disposal andtreatment. Increased population is putting severe strain on sewagesystems, systems are aging and becoming more susceptible to leaks andspills, and costs of spills which include clean-up, mitigation and finesby regulatory agencies are skyrocketing. A recent market analysis by thecivil engineering firm of Brown and Caldwell entitled “What's a SpillWorth?, or a Brief Look at Community Values” surveyed 676 sewageagencies in California to capture the economic value of avoiding spills.The results of the survey revealed, for example, for spills on the orderof 1000's of gallons, agencies were willing to spend $10 per gallon toavoid these spills. For larger spills, agencies were willing to spend$500,000 to more than $1 million to avoid spills reaching receivingwaters such as rivers, lakes or the ocean. It is not uncommon forsanitation agencies to be fined millions of dollars for sewage spills,especially if they are large or reach receiving waters. Sewage spillsalso create serious public relations problems for operating agencies,and it is not uncommon for sewage to back up into residences andcommercial facilities, creating serious liabilities for the agencies andvery costly and time consuming clean-up.

Sewage spills are caused by many problems, but three primary causes areoften cited: grease buildup from illegal discharges by restaurants,other commercial businesses or residences that use fat, lard or greasein food or industrial processing; structural problems in sewage pipescaused by the intrusion of plant roots or pipe breakages that are oftenexacerbated by objects such as rags that are thrown into the sewer; and“infiltration and inflow”, overflows caused by leaks into the systemthat often occur during times of high rainfall or runoff. Sewage spillsoften begin, then, with sewage pipes that are either blocked or are atcapacity and overflowing due to high flows. Currently there is nopractical early warning system to provide system operators acost-effective means to prevent a spill before it happens. Typicallyspills are detected by the community though serendipitous observation ofwater flowing out of manholes or odors around wet areas of ground aroundor above sewage lines. By the time sewage spills are noticed by thepublic, it is too late—the spill has already occurred, and it is just aquestion of how much sewage has spilled into the environment, whetherthe spill has reached clean receiving waters, how much it will cost andhow long it will take to clean-up the problem and how large the fineswill be.

A second major problem for sanitation agencies is a loss of treatmentdue to the killing off of beneficial treatment bacteria at the sewagetreatment plant. A common part of the treatment process is the use ofbacteria to naturally decompose organic materials in the waste water. Ifincoming waste is toxic to the beneficial bacteria, a massive die-offcan occur without warning, and sewage can be spilled or otherwisedischarged that is unknowingly under-treated or untreated. A means toprovide an early warning of toxic materials that are traveling throughthe sewage collection system to the treatment plant could provideoperators with the option of diverting the incoming flow into a holdingpond until the slug of toxic material has dissipated would be useful andimportant to the sanitation industry. In addition, if the source of thetoxic materials could be identified, the source could be stopped orfined as appropriate.

In addition, illegal dumping of materials into manholes is a commonproblem. The source could be illegal operations of commercialestablishments that face large costs associated with disposal ofhazardous waste, including dumping of trucked sewage and septic pumping,or simple vandalism. Covert dumping of illicit drug lab waste is anadditional source of problems. Rather than pay high fees at legaldumping stations, truckers of hazardous waste, include septic waste,could access a remote manhole illegally and dump large quantities ofmaterials with low probability of detection and prosecution. Suchuncontrolled dumping into sewage systems is a major problem for thesanitation industry because the sewage system operators are ultimatelyresponsible for what is dumped into their systems and the operators havelittle or no chance of catching or preventing illegal dumping.

Illegal access to manholes has forced some sanitation agencies to welddown their manholes, creating a significant deterrent to illegal access,but at the same time causing operational problems, including delayed ordeferred maintenance or in the case of an emergency, significant delayin accessing a manhole through the manhole cover.

Current methods exist for the monitoring of level and flow in manholes,for example, two such products are the Hach (Loveland, Colo.) Sigma 1000and the Marsh-McBirney Flo-Dar systems. These methods suffer from one ormore of the following problems: (a) installation requires entry into themanhole, thus high cost and higher safety risk from entering themanhole; (b) the system requires wired communications, thus trenchingaround the manhole; (c) the system requires continuous 120 Volt ACpower, thus trenching around the manhole; (d) the total installation iscostly, limiting the deployment of these systems to no more than a fewselect manholes. A small municipality may have 5,000 to 10,000 manholes,and large municipality may have more than 100,000 manholes. In order toprovide wide coverage, the total cost per manhole must be reasonable.

It is clear that a distinct need exists for a low cost, robust systemand method to provide an early warning system to avoid many of theproblems and costs that sanitation system operators face. Such as systemshould be inexpensive so that it can be widely deployed, provides widearea communications, and is rapid enough to give operators time torespond and prevent catastrophic failure before it occurs and affectsthe community and the environment. This system can also be a platformfor a variety of sensors, for a variety of applications, includingintrusion alarms, closed space monitoring for example for gases, waterquality monitoring, traffic monitoring, and environmental or pollutionmonitoring, and by virtue of distribution in a wide coverage urban area,such a system can have multiple uses in addition to manhole monitoring.

SUMMARY OF THE INVENTION

The present invention provides a system and method for combiningself-contained power, electronics, communications, computationalcapability and sensors into a low cost and low power device integrateddirectly into and mounted on an enclosure barrier such as a manholecover to provide sensing and rapid early warning of problems in theenclosure or around the enclosure barrier. Specifically, the inventionincludes a communications unit to provide communications from the deviceto a remote user of the system; a power source to provide constant andreliable power to the device; a microcontroller that can monitor sensorinputs and control communications and device operations; electronicsthat provide a means to provide appropriate power and current to thecommunications device, microcontroller, and sensors; and sensors whichmonitor parameters inside the enclosure or in the vicinity near theenclosure. The present invention also provides a low cost and low laborinstallation and maintenance process. Instead of expensive andtime-consuming trenching at a site to provide power and communications,the invention provides a means for very low power consumption therebyenabling the use of small standard off-the-shelf battery packs toprovide months of continuous operation, and wireless communications thateliminate the need for wires.

The system and method of the present invention also provides thefollowing: (a) autonomously operations for months without need forexternal power, although external power may be used if it is available;(b) ease of integration and mounting into the enclosure barrier such asa manhole cover so that the operation of the enclosure barrier is notimpeded and physical entry into the enclosure for installation isunnecessary; (c) rapid and reliable communications from the remote siteto various real-time receivers that may include computers and electronicmail, personal digital assistants, phones, cell phones, and pagers; (d)generation of immediate alarms when thresholds of sensors have beenexceeded or switches have been tripped; (e) monitoring of variousconditions in and around the enclosure at short enough time intervals toprovide sufficient time for communications and response in time for theprevention of an activity to be avoided, such as a sewage spill orillegal entry.

In the preferred embodiment, the present invention provides sanitationsystem operators a new way to routinely monitor and detect spills,anticipate overflows, detect illegal entry into the manholes, as well asmonitor other environmental and process parameters of the sewage systemsuch as flows, levels, gas content and sewage content. Furthermore, theinvention detects spills rapidly to cause a response, thereby reducingdamage to the environment, including potential pollution to receivingwaters such as streams, lakes or the ocean. In addition, this inventioncan significantly reduce costs for sanitation system operators who havestrict liability for spills occurring in their systems. Because thesystem is integrated directly into the manhole cover, there is noinstallation in the manhole shaft itself and no need to enter themanhole, further reducing risk and costs of installation.

In another embodiment, the present invention can be used as a monitorfor the environment surrounding the enclosure. For example, with themounting on the underside of manhole covers, the invention can also beused to monitor street traffic, air quality in urban areas, or otherenvironmental parameters. The invention could serve more generally as asensor platform for a suite of sensors, which are directed at areasbelow the manhole, above the manhole, or both.

The foregoing, together with other features and advantages of thepresent invention, will become more apparent when referring to thespecification, claims and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood from the followingdetailed description of an exemplary embodiment of the invention, takenin conjunction with the accompanying drawings in which like referencenumerals refer to like parts and in which:

FIG. 1 shows a schematic block diagram of one embodiment of the presentinvention;

FIG. 2 shows a schematic diagram of a typical manhole cover with theinstrument and antenna attached directly to the manhole cover;

FIG. 3 shows a top view of a layout of the battery, electronics, tiltsensor and communications in a housing;

FIG. 4 shows a side view of the same layout in the housing, includingthe ultrasonic sensor;

FIG. 5 shows a schematic drawing of the antenna mounting on the manholecover;

FIG. 6A shows the flow diagram for the tilt sensor in one embodiment ofthe invention; and

FIG. 6B shows the flow diagram for the ranging sensor in one embodimentof the invention.

DETAILED DESCRIPTION

The present invention provides a system and method for combiningself-contained power, electronics, communications, computationalcapability and sensors into a low cost and low power device integrateddirectly into and mounted on an enclosure barrier such as a manholecover to provide sensing and rapid early warning of problems in theenclosure or around the enclosure barrier. The sensors include, but arenot limited to, a level sensor, a flow sensor, a pressure sensor, aranging sensor, an ultrasonic ranging detector protected by a waterresistant fabric, a gas sensor, an odor sensor, a temperature sensor, anoptical monitor, such as a video camera, still camera or an infraredsensor. Furthermore, the sensors can be physically disconnected from themanhole cover and mounted on the walls or the floor of the manhole. Forexample, a float switch may be remotely located at the bottom of themanhole with an infrared or ultrasonic means of contacting the housing.In the case of a the float switch no power is consumed until the floatswitch closes with rising fluid level, thus conserving power, such as abattery. Additional types of sensors can be physically disconnected fromthe manhole cover and communicate with the housing through wired orwireless means within the enclosure or manhole.

The invention includes a communications unit to provide communicationsfrom the device to a local or remote user of the system; a power sourceto provide constant and reliable power to the device; a microcontrollerthat can monitor sensor inputs and control communications and deviceoperations; electronics that provide a means to provide appropriatepower and current to the communications device, microcontroller, andsensors; and sensors which monitor inside the enclosure or the vicinitynear the enclosure. The present invention also provides a low cost andlow labor installation and maintenance process. Instead of expensive andtime-consuming trenching at a site to provide power and communications,the invention provides a means for very low power consumption therebyenabling the use of small standard off-the-shelf battery packs toprovide months of continuous operation, and wireless communications thateliminate the need for wires. Solar cells or a rechargeable battery thatis recharged using direct electrical connections or capacitive orinductive connections from a portable device can also provide power.

The microcontroller is programmed with a command set that defines thestates of operation of the system. Such defined states include, but arenot limited to initial testing mode, field installation mode, normaloperation mode, change reporting frequency, change sampling frequency,return current status mode, return historical data mode, resethistorical data mode, change location text string, change alarmdestination address strings, reset the communications channel, enable ordisable alarms and send messages to system users. The commands come frommanual commands provided by system users or from automatic scripts thatrun in an application server computer.

Unless otherwise indicated, the following terms will have the followingmeanings:

The term “manhole” shall be taken in its broadest sense to include,without limitation, underground vaults, for example manholes or utilityvaults, as well as any other enclosed area, underground or above ground,that has instrumentation or materials or aspects in or about theenclosed area that may be monitored.

The term “manhole cover” shall be taken in its broadest sense toinclude, without limitation, covers for underground vaults, for examplemanholes or utility vaults, as well as enclosure barriers such as doorsor walls for any other enclosed area, underground or above ground, thathas instrumentation or materials or aspects in or about the enclosedarea that may be monitored.

The term “hardware enclosure” shall be taken in its broadest sense toinclude, without limitation, the box and its contents that hold some orall of the following: the electronics, the power supply, input/outputconnections, the communications device, the microcontroller, sensors,and any environmental materials used to make the box rugged and weatherand water proof.

The term “application server computer” shall be taken in its broadestsense to include, without limitation, a computer and communicationssystem that can receive messages from the installed field unit andforward the messages to email addresses, pagers, personal digitalassistants, cell phones and other means of notification of responsibleparties. The server can also direct commands from system users out tothe installed field units. The server also provides alarmacknowledgement, statistical record keeping, customer administration,report generation, maintenance record keeping and alerting, and securitymanagement. The application server computer can also translate tersemachine-to-machine messages into a format that is understandable by asystem user.

The term “system user” shall be taken in its broadest sense to include,without limitation, people who are using the system to sense and monitorvarious environmental and process parameters in their area of interest,for example, the manager or operator of a sanitation utility.

The term “alert” shall be taken in its broadest sense to include,without limitation, a message sent to a system user to notify them of acondition of concern in their system.

The term “installed field unit” shall be taken in its broadest sense toinclude, without limitation, the installation of the hardware enclosureon an enclosure barrier such as a manhole cover, including the antennaand all sensors required for operation of the unit in its intendedmanner.

The central component of the present invention is the instrumentedmanhole cover. The instrumented manhole cover integrates power,communications, electronics, microcontroller(s), and sensors into acompact low power and low cost package that mounts easily onto a manholecover, providing a universal platform for sensors that can operate belowor inside the manhole cover or above or outside the manhole cover. Thepurpose of this instrumented manhole is to communicate critical ortime-sensitive information about the monitored aspects of theenvironment around the manhole. While the preferred embodiment discussedhere involves the monitoring for sewage waters, the invention can alsobe applied, without limitation, to any monitoring application concerningan enclosed area that contains a critical asset as well as enclosedareas that can be used to monitor the environment external to theenclosure. It is presumed that in general the monitored area isdifficult to provide electric power and wired communications to.

The present invention will now be described hereinbelow, and withreference to the drawings. FIG. 1 shows a schematic diagram of thecomponents of a preferred embodiment of the system. Referring to FIG. 1,the major hardware components of the device are integrated into a singlehousing 10, which is affixed to the underside of a device such as, amanhole cover, an enclosure cover, a door, a window and a wall, andincludes the following components: a high capacity battery 11 (althoughthis power can also be provided by standard AC line power or othersources) which has sufficient capacity to provide power for at leastseveral months and which provides power for a digital microcontroller 12and a two-way wireless radio module 13 through a low voltage powerconverter 14. The digital microcontroller 12 communicates to the two-waywireless radio module 13 through a digital connection 15. Communicationports for external sensors for the hardware package 10 are providedeither through an analog to digital (A/D) converter 16 for sensors suchas temperature, pressure, chemical sensors, or other variable parameters21 that provide an analog output or directly to the digitalmicrocontroller 12 for range and position sensors 22 or intrusion alarms23 that provide digital or switch signals. Output ports exist on thedigital microcontroller 12 to control output devices such as valves oractuators 24. The two-way wireless digital radio module 13 communicatesvia radio waves 30 (although this communication can also be done throughland lines) through either a worldwide or national wireless radionetwork, or through an existing local radio network 40. This wirelessnetwork 40 then communicates either through a wire line or wirelessly toa central server 50 that is provided by the network provider andreceives the parameters transmitted from the external antenna. (Theantenna is designed and tuned to operate in close proximity to themetallic surface of a manhole cover.) The central server 50 communicatesthrough an Internet connection 60 to the application server computer 70,which keeps the database for the operation of the system 81 as well asall the application logic for the system 82, including the user'sinterface 90. The user's interface can include many devices or methods,including without limitation, pagers, cell phones, personal desktopcomputers via email, laptop computers using wireless connections, landline phones, and audio and visual alarms. Furthermore an additionalantenna may be located on the underside of the manhole cover for directcommunications to the central server through the ground or in the eventof the inversion of the manhole cover.

In an alternative embodiment, data or information from multiple manholescan be compiled. This information can be compiled using local radio,wired, infrared, or acoustic communications that coordinate alarmslocally for transmission to the application server computer by a shared,long range communication system. The application server computer canalso provide alarm forwarding to system users and can establish thealarm state in a database. In turn the system user can acknowledge thatalarm which notifies the installed field unit or housing and records theacknowledgement in the application server computer database. Thedatabase can then be queried to determine the responsiveness of thesystem user to an alarm. Additionally, the installed field unit canconserve battery power by varying the time between samples as a functionof season of the year, manual commands from the application servercomputer, or observation of the physical conditions measured over aperiod of time.

The preferred embodiment of the invention, as applied to sewer manholecovers, is described hereinbelow. This embodiment is in no way limitingof the invention and serves solely as an illustrative example of theapplication and use of the present invention.

This preferred embodiment of the present invention includes two primarysensors: a tilt and acceleration (accelerometer) sensor that can detectthe movement of the manhole cover from the resting position, and anultrasonic ranging device that detects the level of the water in thesewage manhole. Additionally, an optical means, a contact switch and amagnetic switch can be utilized to detect if the manhole cover has beenmoved or opened. All of the power, communications, electronics,microcontroller and sensors are combined in a small box—the “housing”that is affixed directly to the bottom of the manhole in a way that doesnot impede opening of the manhole cover, or require entry into themanhole for installation. The main components of the system are shown inFIG. 2. Typical manhole covers 100 are made of steel or cast iron, andif they are “traffic rated”, that is, capable of supporting loads fromroad vehicles, they are very heavy and rugged and include support vanes120 on the bottom of the cover. The housing 110 is mounted on the bottomof the manhole using a mounting bracket that is screwed into the manholecover, or directly mounted onto the manhole cover with screws, or gluedonto the manhole cover with traffic rated epoxy. The housing 110 issmall enough to be protected from impact by the manhole ribs 120 orextensions from the manhole ribs. The only external connection for thehousing is the antenna 130, which is connected through a small hole,drilled in the manhole cover. The antenna cable 140 connects the housing110 to the external antenna 130, which transmits the parameters to acommunication device, such as a cell phone, a pager, a personal digitalassistant, or a personal computer.

FIG. 3 shows a top view of a preferred schematic layout of thecomponents of the housing 200. All of the components of the hardware arepackaged in a NEMA-4 (produced for example by Hoffman, Anoka, Minn.) orbetter rated enclosure 210 that is rugged and provides water resistanceand is environmentally sealed. In FIG. 3, the high capacity battery 220is chosen to maximize the capacity of the battery in amp-hours (A-H) forthe volume of the battery. Typical batteries that can be used in thepreferred embodiment of the invention are primary lithium batteries. Forexample, a six-volt supply with about 10 A-H can be constructed of fourseries pairs of AA three-volt lithium cells in parallel using standardoff-the-shelf batteries from, for example, the Duracell® Lithium Model245 from the Duracell® Corporation. With a total target typical amperagedraw of the housing 200 of about two milliamps (mA), a battery pack ofabout 10 A-H capacity can provide sufficient power for more than sixmonths of continuous operation. Standard alkaline batteries are analternative primary battery type. While primary batteries 220 are thepower source of choice for low cost, small package size applications,the present invention is not limited to this type of power source. Ifexternal AC or DC power is readily available, it can be used as asubstitute, or rechargeable batteries, such as nickel metal hydridebatteries can be used in conjunction with a low current trickle chargefrom an adaptation such as a solar cell to charge the batteries duringdaylight hours.

The high capacity battery 220 in FIG. 3 provides power through a lowvoltage power converter 260 to two sources in the hardware package, thedigital microprocessor 240 and the two-way digital radio module 250.Typically the battery 220 is at 6 volts, and the microprocessor 240 andthe two-way radio module 250 operate at lower voltages. Operatingvoltages are minimized, and hardware is put into “sleep” mode whenpossible in order to minimize power consumption. In the preferredembodiment, the microprocessor 240 is a Basic Stamp 2pe (Parallax®Corporation), and the two-way digital radio 250 is a Karli ReFlex pagingunit (Advantra® Corporation). A coaxial connector cable 270 is connectedto the Karli unit 250, and this connector leads to the external antenna,which is mounted, on the manhole cover. The Karli unit 250 is capable ofmeasuring the ambient temperature as well as the input voltage to thepager, thereby providing additional sensing capability that can bereported and stored by the microprocessor.

The low voltage power converter 260, the Karli two-way pager 250, andthe microprocessor 240, are all mounted on a single printed circuit (PC)board 230. The tilt and acceleration sensor 280 is also mounted on thisPC board. The tilt and acceleration sensor 280 acts as a switch, whichis either open (normal state) or closed (the sensor has been tilted oraccelerated). The state of the tilt and acceleration sensor 280 ischecked typically once every second, but this frequency is variable andapplication specific. If the state of the tilt and acceleration sensor280 is found to be closed, a signal is sent through the pager 250 to thewireless network and the time and date of this closed state is stored inthe microprocessor 240.

FIG. 4 shows a side view of the housing 300, analogous to FIG. 3 showingthe top view. The battery 310 provides the power for the housing. Poweris provided for the microprocessor 330 and the two-way pager 340 on theelectronics board 320, and the ultrasonic ranging sensor 350. An exampleof a low cost ultrasonic ranging sensor is the PING ultrasonic sensor(Parallax® Corporation), which provides range information to maximumrange of about 11 feet, which covers the majority of manhole depths. Awaterproof or water resistant cover 360, which does not adversely affectthe performance of the ultrasonic sensor 350, is placed in front of theultrasonic sensor. At intervals of approximately once every ten minutes,the ultrasonic sensor 350 is turned on and makes a measurement of rangeusing ultrasonic waves 370. If the range result comes back as differentfrom normal, a signal is sent through the pager 340 to the wirelessnetwork.

FIG. 5 shows the antenna mounting on the manhole cover 400 in thepreferred embodiment of the invention. A small hole is drilled in themanhole cover and a coaxial cable 410 connected directly to the pager inthe housing comes from underneath the manhole cover and is connected toa low profile strip antenna 420. The strip antenna 420 is offset fromthe manhole cover top surface by a dielectric spacer 430, typically 1 mmto 5 mm thick. The spacer, strip antenna, and connection are togetherencased in traffic-rated epoxy 440 of the type used to attach reflectorsto road surfaces.

In the preferred embodiment of the present invention, radio signals aresent through a commercial two-way paging network known as ReFLEX,developed by Motorola® Corporation. The ReFLEX network provides asecure, robust two-way communications method-using signals between 900MHz and 1000 MHz. The ReFlex network includes geographically distributedtransceivers that communicate both to the installed field units by radioand to the Internet with wireline connections. This allowscommunications from any Internet connected system (such as theapplication server computer) to securely communicate to installed fieldunits. The ReFLEX network protocols are licensed from the AmericanAssociation of Paging Carriers. ReFLEX communications have the advantageof wide geographic dispersal, generally superior to cellular coverageand lower monthly costs. The ReFLEX network does require sophisticatedsoftware for supporting both the installed field devices and theapplication server computer. The ReFLEX system is designed to pass tersedigital messages that identify specific status information, such as asecurity alert or a water level that is too high. This information maybe communicated and coded in as little as one or two bytes ofinformation. The message is marked with a unique identifying installedunit number and so further identification is not required. Theapplication server can reformat a terse one or two byte message into amore informative message for sending to a system user. A hexadecimal“C5” might be translated into “Security Entry Alert” and the uniqueinstalled filed unit number of “345123” might be translated to “5400block of Main street”. This combined message would be sent by email, orShort Messaging Service (SMS) to a cell phone as a text message, to apager, or to a computer based Supervisory Control and Data Acquisition(SCADA) system that is monitored by system users. The intent is the useof the ReFLEX network for rapid notification of responsible parties in acontinuous, geographically independent way.

In the preferred embodiment of the present invention, which is just onepossible configuration and application of the invention, communicationsoccur in the one of the following manners, as examples, withoutlimitation. First, as a default, each installed hardware package at agiven manhole cover sends a status message to the application servercomputer two times each day. The purpose of this message is to assurethe system user that each installed hardware package and the supportingwireless communications system is working properly. Referring to FIG. 1,a maintenance alert is sent to the system user from the applicationserver computer 70 if the expected message from the installed housing 10does not occur in a timely manner, indicating a potential problem witheither the communication to the site or instrumentation at the site. Asecondary purpose of this message is to send nominal operatingparameters, including without limitation, the temperature history at thesite, the wireless signal level history at the site, and the batteryvoltage or input voltage level. Second, the system user can send amessage to the installed hardware package essentially asking for aresponse to the system user that the installed hardware package isoperating normally. Third, the system user can request that theinstalled hardware package send back data stored in the microprocessormemory, including without limitation temperature history, batterylevels, wireless signal levels, alarm types and times, and currentstatus of the sensors. Fourth, the system user can send a message to theinstallation site changing the operational parameters, including withoutlimitation thresholds for alarms, frequency of reporting, frequency ofinterrogating the sensors, nominal manhole depth, addresses formaintenance messages and alerts and the address of the installed fieldunit. Fifth, the installed field unit can send self-generatedmaintenance messages or alert messages to the wireless network based onpre-set conditions. An example of how maintenance messages and alertscan be sent is discussed herein below.

As an example, in the preferred embodiment of the present invention, twosensors are used: a tilt/acceleration sensor set to alarm if the manholecover is tilted or moved from its resting position, and an ultrasonicranging detector that measures the height of the water in the manhole.The following procedures are meant to be illustrative—these can behandled in a variety of ways, and the following description is notintended to limit the scope of the invention. FIG. 6A shows the flowdiagram and logic for sending an alert based on the state of the tiltsensor. The tilt sensor is a binary device that acts as a switch. Whenthe tilt sensor is at normal conditions, it is open. When it is tiltedor accelerated, it is closed. The state of the tilt sensor is read 500.If the tilt sensor is open 510, the microcontroller waits one second 530(although any time interval greater than the cycle time of themicroprocessor can be used) and reads the tilt sensor again. Thisfrequency is high enough to ensure that if the manhole cover is moved,the tilt sensor will capture the change in state. If the tilt sensor isread to be closed 520, the time and date of that event is logged in themicrocontroller and an alert is sent to the paging network system fordistribution to the system user's based on a pre-arranged protocol,including, for example law enforcement in the case of an illegal entry.A minute passes 531 (although this interval can be longer or shorter)and the tilt sensor is read again and the process starts over. FIG. 6Bshows the flow diagram for sending an alert based on the reading of theultrasonic ranging sensor. Since the ultrasonic sensor consumes power,it is turned on only when used. This is shown in FIG. 6B as 540. Oncethe ultrasonic detector is turned on, it immediately makes a rangingmeasurement 550. There are at least four outcomes of the rangemeasurement: it is “in range” 551, meaning the measurement matches theexpected value of distance to the bottom of an unflooded manhole asstored in the microprocessor, for example; it is “low” 552, meaning thedistance is shorter than expected, indicating a possible floodingcondition; or it is “high” 553 or is at “maximum range” 554, bothconditions suggesting that the ultrasonic sensor is not operatingproperly and may require maintenance. In the case of “in range” 551, theultrasonic sensor is turned off 560, and another measurement is made in10 minutes 570 (although this time interval can be anything greater thanthe cycle time of the microprocessor) and the process repeats. This isthe normal and expected condition. In the case of a “low” measurement552, a repeat measurement 580 is made to check this “low” measurementand decrease the incidence of false positives. If the measurementreturns as a low measurement 582, an alert is sent to the network 590 tobe delivered to the system's users based on a pre-arranged protocol,including without limitation, for example, to the system operator'spager and cell phone and the system operator's email. If the repeatmeasurement 580 returns “in range”, then it is assumed that the previousmeasurement was an error, the ultrasonic detector is turned off 560, thenominal 10 minute wait period repeats 570, and the sequence starts over.This repeated measurement process can occur any number of times withoutlimitation to reduce the chances of false positives as well as to trackthe rising water in the manhole as a function of time. In the cases of a“high” measurement 553 indicating that the nominal range increased,which is physically unlikely or a “max range” measurement 554 occurs, amaintenance message is sent to the network 555 to be delivered to thesystem's users on a pre-arranged protocol.

Although the foregoing invention has been described in some detail byway of illustration and example for the purpose of clarity andunderstanding, it will be apparent to those of ordinary skill in the artin light of the disclosure that certain changes and modifications may bemade thereto without departing from the spirit or scope of the intendedclaims.

1. A remote sensing system comprising: a housing having communicationports; one or more analog sensors connected to the communication ports,the analog sensors monitoring parameters in the vicinity of the housing;an analog/digital (A/D) converter in communication with the analogsensors through the communication ports; a microcontroller connected tothe analog/digital (A/D) converter within the housing, themicrocontroller comprising instructions for receiving the parametersfrom the analog/digital (A/D) converter and for communicating theparameters to a two-way communication module through a digitalconnection; an external antenna connected to the two-way communicationmodule for transmitting the parameters to a communication device; and apower means for providing power at least to the microcontroller andanalog/digital (A/D) converter.
 2. The system of claim 1 furthercomprising a central server away from the communication device, whereinthe central server receives by way of the communication device theparameters transmitted from the external antenna, and wherein thecentral server is in communication with an application server computerthat stores the parameters.
 3. The system of claim 1 wherein theparameters are environmental or process parameters.
 4. The system ofclaim 1, wherein the communication device is selected from the groupconsisting of: cell phone, pager, personal digital assistant, andpersonal computer.
 5. The system of claim 1 wherein the housing ismounted on a device selected from the group consisting of: an enclosurecover, a door, a window, a wall and a manhole cover.
 6. The system ofclaim 1, wherein the analog sensors comprise at least one analog sensorselected from the group consisting of a level sensor, a flow sensor, apressure sensor, a ranging sensor, an ultrasonic ranging sensor, a gassensor, a humidity sensor, a temperature sensor, a tilt sensor, anacceleration sensor, a chemical sensor, and an optical monitor.
 7. Thesystem of claim 1, the system further comprising one or more digitalsensors connected to the communication ports.
 8. The system of claim 1,wherein the housing is mounted on a device selected from the groupconsisting of: an enclosure cover, a door, a window, a wall and amanhole cover; the system comprising at least one analog sensor thatmonitors if the device has been moved, and wherein, if the device hasbeen moved, an alarm is triggered to notify a user.
 9. The system ofclaim 1, wherein the housing is mounted on a device selected from thegroup consisting of: an enclosure cover, a door, a window, a wall and amanhole cover, the system comprising at least one analog sensor thatmonitors for entry in a space near the device, and wherein, if entry hasbeen detected, an alarm is triggered to notify a user.
 10. The system ofclaim 1, wherein the microcontroller is programmed with a command setthat defines states of operation selected from the group consisting ofinitial testing mode, field installation mode, normal operation mode,change reporting frequency, change sampling frequency, return historicaldata mode, reset historical data mode, change location text string,change alarm destination address strings, reset the communicationschannel, enable alarm, disable alarm and send message to system users.11. The system of claim 1, wherein the housing is mounted onto anexisting manhole cover already in place at a manhole.
 12. The system ofclaim 1 further comprising output ports on the microcontroller tocontrol output devices.
 13. The system of claim 12, wherein at least oneoutput device is in analog communication with the analog/digital (A/D)converter through the output ports.
 14. The system of claim 12, whereinthe output devices are selected from the group consisting of valves andactuators.
 15. The system of claim 1, wherein the housing is mounted ona manhole cover, wherein at least one of said analog sensors is aranging sensor for measuring the height of water in an enclosureselected from the group consisting of: underground vault, manhole,utility vaults, underground enclosed area, above ground enclosed area.16. The system of claim 15, wherein if the ranging sensor detects theheight of the water in the manhole above a predetermined level, an alertis sent to a user.
 17. The system of claim 1, wherein at least one ofsaid analog sensors or at least one digital sensor is physicallydisconnected from the manhole cover and mounted on a wall or floor ofthe manhole.
 18. The system of claim 1, wherein the microcontroller, alow-voltage power converter, and a tilt and acceleration sensor aremounted on a single printed circuit board.
 19. A remote sensing systemcomprising: a housing having communication ports for sensors, thesensors monitoring parameters in the vicinity of the housing; amicrocontroller within the housing for communicating the parameters to atwo-way communication module through a digital connection; an externalantenna connected to the two-way communication module for transmittingthe parameters to a communication device; a power means for providingpower to the housing; and an additional antenna connected to the two-waycommunication module for direct communications to the firstcommunication device or another communication device through the ground.20. A remote sensing system comprising: a housing having communicationports for sensors, the sensors monitoring parameters in the vicinity ofthe housing; a microcontroller within the housing for communicating theparameters to a two-way communication module through a digitalconnection; an external antenna connected to the two-way communicationmodule for transmitting the parameters to a first communication device;a power means for providing power to the housing; and at least oneanalog or digital sensor configured to be mounted on a wall or floor ofa manhole.